AN AXIAL-EMISSION BENT BEAM GAUGE

Upon the basis of the axial-emission ionization gauge (AEG)1, a new axial-emission bent beam gauge (AEBBG) has been developed by adding small deflecting electrodes between the grid and the front of the collector. Due to the deflection of the residual photo-current to the ion collector, the pressure limit of the AEBBG is less than less-than-or-equal-to 10(-12) Pa at I(e) = 2mA, V(g) = 500 V, V(f) = 300 V, V(d) = -320 V, V(c) = 0 and V(s) = 500 V. In comparison with helmer's bent beam gauge, the AEBBG has the advantage of a high sensitivity (0.25 Pa-1 for N2) and simple electrode construction allowing easier degassing and a lower filament temperature. All these make the AEBBG more suitable for the measurement of uhv and xhv. Furthermore, the upper limit can be extended to 2.7 X 10(-2) Pa when I(e) is decreased to 0.2 mA.Materials Science, MultidisciplinaryPhysics, AppliedSCI(E)